1. Field of the Invention
The present application relates generally to an improved data processing apparatus and method and more specifically to an apparatus and method for performing a markup language node level hash join operation for evaluating a query language query.
2. Background of the Invention
Markup languages, such as the Extensible Markup Language (XML), are languages for generating electronic applications, documents, or the like, by combining text and extra information about the information. This extra information includes structure, layout, or other information, and is expressed using markups, such as tags or the like, which are typically intermingled with the primary text. XML has as a primary purpose to facilitate the sharing of structured data across different information systems, particularly via the Internet. XML is often used to generate electronic documents, such as Internet web pages or the like, these electronic documents typically having a structured format.
As the amount of information that is presented in electronic documents increases, electronic document repositories, collections, databases, etc. have been devised for storing these electronic documents. Query languages, such as XQuery and Structured Query Language (SQL) have been developed for querying such repositories to retrieve electronic documents meeting desired criteria. Mechanisms have been devised for evaluating queries provided in such query languages.